To fetch selective fields from DATABASETABLE into Internal TABLE

Question

Hi Friends,
I have declared an internal table with fields for e.g. A , B , C , D.
This does not have any records as of now.
I have to fetch data from a DATABASE TABLE with fields A , B , X , Y , Z having records .
I only need records for fields A B fron DB table.Can any one pls tell how can I do that with performance issues in mind as lots of records are there.
I had written a query where:
SELECT A B from dbtab
                    into CORRESPONDING FIELDS of table it_table.
It_table i had defined with only two fields A B.
Is this correct?
Please tell wats the way to do it as I am new to ABAP.
THANKS in ADVANCE..

Answer 1

Hi.....
What mentioned in all above answers is very helpful for ur requirement...
and...
   Here some Steps to increase the performence of your programs...
>Use Select Single when only one row is expected
>Use Select Where rather than Selectu2026Check
>Use Select with aggregate functions (SUM, MAX, MINu2026)
>Use a View instead of nested Selects
>Use Select column specific instead of select * for few fields
>Use Selectu2026Into Table rather than Select...Move Corru2026Apend
>Use Join extension with Select if possible
>Use special operators (CO, CA, CS) rather than code your own
>Use Delete Adjacent Duplicates rather than manual processing
>Specify key fields for Readu2026Binary Search
>Use Loop At Where rather than Loop Atu2026Check
>Copy Internal Tables with TAB_DEST() = TAB_SRC()
>Specify the sort key as restrictively as possible
>Use Append To, Insert Into, Collect Into rather than Move
>Compare tables with If Tab1() = Tab2()u2026
>Use Delete ITAB Whereu2026 instead of Loop At ITAB Whereu2026Delete..
>Use Case statements instead of If-constructions
>Use Call Functions wisely, Performs use less memory
>Use While instead of Do Exit
>Use Type I for Indices
>Keep Occurs clause realistic or use 0
>Use COMMIT WORK as appropriate to free the Data Base and preserve work
>
>Avoid:
>Using Shift inside a While-loop
>Leaving unneeded declarations in your program
>Using Move-corresponding for just a few fields
>Excessive nested includes within function calls
>Using DB field names if the value will be changed
>Using Occurs clause if only the header is needed
Thanks,
Naveen.I